Problem Converting byte[] to Bitmap c#

Question

Hi,

I have an urgent problem, i'm trying to convert a byte array to a bitmap but it always shows me: System.ArgumentException: Parameter is not valid.

my code is as follow:

Im passing the bytes through a webservice with:

 string DecodedString = string.Empty;
 DecodedString = System.Text.Encoding.GetEncoding(1251).GetString(bytes);
 sResult = sResult + "<Photo>" +XmlConvert.EncodeName(DecodedString) + "</Photo>";

and in my webPage:

byte[] bytes = (Byte[])System.Text.Encoding.GetEncoding(1251).GetBytes(XmlConvert.DecodeName(xDocument.SelectSingleNode("Response/Images/Photo").InnerText));
    System.IO.MemoryStream ms = new System.IO.MemoryStream(bytes);

    System.Drawing.Bitmap b = new System.Drawing.Bitmap(ms);//(System.Drawing.Image.FromStream(ms));

Thanks in Advance..

Answer 1

Try passing the string as a Base64:

string DecodedString = string.Empty;
DecodedString = System.Convert.ToBase64String(bytes)
sResult = sResult + "<Photo>" +XmlConvert.EncodeName(DecodedString) + "</Photo>";

...

byte[] bytes = System.Convert.FromBase64String(xDocument.SelectSingleNode("Response/Images/Photo").InnerText);
System.IO.MemoryStream ms = new System.IO.MemoryStream(bytes);
System.Drawing.Bitmap b = System.Drawing.Image.FromStream(ms);

You also won't need to use XmlConvert to encode/decode the string.

Answer 2

I had a similar problem recently, but using Silverlight. I ended up needing to create a Custom HTTP Handler in order to pass the byte[] that defined the image back as a stream.

See http://www.dotnetcurry.com/ShowArticle.aspx?ID=220

Edit: This allows you to avoid worrying about XML encoding, and passes the image back in Binary form... YMMV

Answer 3

Now it shows:

An exception of type 'System.FormatException' occurred in App_Web_qfrgklax.dll but was not handled in user code

Additional information: Invalid character in a Base-64 string.

When:

byte[] bytes = System.Convert.FromBase64String(xDocument.SelectSingleNode("Response/Images/Photo").InnerText);

Answer 4

ok, my code in the webservice is now [without the encode]:

string DecodedString = string.Empty;
    DecodedString = System.Convert.ToBase64String(bytes);
    sResult = sResult + "<Photo>" + DecodedString + "</Photo>";

and my page [without the decode]

byte[] bytes = System.Convert.FromBase64String(xDocument.SelectSingleNode("Response/Images/Photo").InnerText);

    System.Drawing.Bitmap b;

    using (System.IO.MemoryStream ms = new System.IO.MemoryStream(bytes))
    {
       b = new System.Drawing.Bitmap(System.Drawing.Image.FromStream(ms));
    }

But its still showing Parameter is not valid.

in the next line:

b = new System.Drawing.Bitmap(System.Drawing.Image.FromStream(ms));

Answer 5

And i've noticed tha this Parameter is not valid exception is always happening in the same line of code:

System.Drawing.Image.FromStream(ms));

And i can clearly see that the from stream method is receiving the parameter its expecting.

But i can't find the right way to do it yet.

Answer 6

Try this:

byte[] bytes = System.Convert.FromBase64String(xDocument.SelectSingleNode("Response/Images/Photo").InnerText);
System.Drawing.ImageConverter imageConverter = new System.Drawing.ImageConverter();
Image image = imageConverter.ConvertFrom(bytes) as Image;
System.Drawing.Bitmap b = new System.Drawing.BitMap(image);

EDIT

Take a look at this:

Transfer any files on Web services by c#

Answer 7

According to MSDN:

ArgumentException - The stream does not have a valid image format

I believe your problem is in the original byte[] array you are passing to the web service. According to one of your comments, you did:

System.IO.FileStream fs = new System.IO.FileStream(sPath, System.IO.FileMode.Open, System.IO.FileAccess.Read);
int streamLength = Convert.ToInt32(fs.Length);
bytes = new byte[streamLength];
fs.Read(bytes, 0, streamLength);

fs.Read returns the number of bytes that have been read into the byte array; it doesn't always read the entire file!
Try using the StreamFile method from http://www.dotnetspider.com/resources/4515-convert-file-into-byte-array.aspx. (First result of Google search)

Answer 8

Ok, here is the entire webservice code:

    byte[] bytes;
    System.IO.FileStream fs = new System.IO.FileStream(sPath, System.IO.FileMode.Open, System.IO.FileAccess.Read);
    int streamLength = Convert.ToInt32(fs.Length);
    bytes = new byte[streamLength];
    fs.Read(bytes, 0, streamLength);

    .......
    Here i form the response xml. 
    .......


 string DecodedString = string.Empty;
    DecodedString = System.Convert.ToBase64String(bytes);
    sResult = sResult + "<Photo>" + DecodedString + "</Photo>";

And decode string is the picture i want to display.

The thing is that without using a web service it works i mean without the webservice the picture shows.

Answer 9

FINALLLYYYY,

i did it, with the help of all of you, here is my page code

 byte[] bytes = System.Convert.FromBase64String(xDocument.SelectSingleNode("Response/Images/Photo").InnerText);


   System.IO.MemoryStream ms = new System.IO.MemoryStream(bytes);

   System.Drawing.Bitmap b = new System.Drawing.Bitmap(ms); //(Bitmap)System.Drawing.Image.FromStream(ms);

   System.Drawing.Imaging.FrameDimension frameDim;
   frameDim = new System.Drawing.Imaging.FrameDimension(b.FrameDimensionsList[0]);


   int NumberOfFrames = b.GetFrameCount(frameDim);
   string[] paths = new string[NumberOfFrames];

   for (int i = 0; i < NumberOfFrames; i++)
   {
     b.SelectActiveFrame(frameDim, i);

     System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(b);
     paths[i] = imagePathfile.Remove(imagePathfile.Length - 4, 4) + i.ToString() + ".gif";

     bmp.Save(paths[i], System.Drawing.Imaging.ImageFormat.Gif);
     //bmp.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);
     bmp.Dispose();
   }

    Image1.Src = paths[0];
    //Check if there's more than 1 image cause its a TIFF
    if (paths.Length>1)
    {
      Image2.Src = paths[1];  
    }

Thanks to all of you..... Luis.

Answer 10

Thanks for this..its working for me..but the problem am facing is that the image displaying does not have same original clarity..Can any one tell me what is the problem? What should i do to maintain the same original clarity after decode..

Tnx in advance. Sri

Answer 11

actually i had been meet this problem, In my case, when i use IE browser, it is ok but when use another browser it always have the same error.

"Parameter is not valid exception is always happening in the same line of code: System.Drawing.Image.FromStream(ms));"

So i think it seems this issue depend on browser and type of image (JPEG,JPEG2000).

Answer 12

you can do this by simply creating a memory stream MemoryStream ms = new MemoryStream(bytes); Image img = System.Drawing.Image.FromStream(ms); for more detail visit this post